package JMU3.BianChen.ti401;

import java.util.Random;
import java.util.Scanner;

/**
 * @author Lenovo
 */
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        long seed=scanner.nextLong();
        int n= scanner.nextInt();
        Random random=new Random(seed);
        int count=0;
        for(int i=0;i<n;i++){
            double x= random.nextDouble()*2-1;
            double y= random.nextDouble()*2-1;
            if(Math.sqrt(Math.pow(x,2)+Math.pow(y,2))<1){
                count++;
            }
        }
        double PI=4.0*count/n;
        System.out.println(PI);

    }
}
